Set up a double boiler on the stove.
Measure out the tallow and coconut oil into a large bowl and set it over the double boiler.
Meanwhile measure out the calendula infused sweet almond oil in a separate bowl.
Measure out the lye in a small container and the calendula tea into a separate container.
Slowly sprinkle the lye over the calendula tea while stirring gently until the lye is fully dissolved. Set the lye mixture aside to cool.
Measure out the essential oil blend and set it aside.
Once the hard oil have melted in the double boiler, remove the bowl from the heat and stir in the calendula infused sweet almond oil.
When the lye mixture and oil mixture have cooled pour the lye water into the oil mixture, stirring to combine them for a minute.
Using an immersion blender combine the mixture until the soap reaches "trace."
Add the essential oil blend and oil-soaked calendula petals. Blend it a little longer until they are fully combined.
Pour the mixture into the soap mold.
Sprinkle with dry calendula and/or cornflower petals to decorate if desired.
Cover and set in a cool place until the soap has hardened enough to remove from the molds, usually 48 hours.
Cut the soap into bars and cure for 4-8 weeks. The longer you cure the bars, the harder the final bars will be and the longer they will last.